@article {Callaway525,
author = {Callaway, Ch.},
title = {A Preliminary Inquiry into the Genesis of the Crystalline Schists of the Malvern Hills},
volume = {43},
number = {1-4},
pages = {525--536},
year = {1887},
doi = {10.1144/GSL.JGS.1887.043.01-04.39},
publisher = {Geological Society of London},
abstract = {Introduction.The igneous origin of some foliated rocks was first suggested to me by the granite of Northern Donegal*. The Rev. E. Hill, F.G.S., had previously noticed{\textdagger} a gneissic structure in the granite of Guernsey. Mr. J. J. Harris Teall, F.G.S., has described foliation in basic rocks in the North-western Highlands{\textdaggerdbl} and at the Lizard{\textsection}. Schistosity in granitoid rocks has also been observed in the Alps by Professor Bonney, F.R.S. Besides English workers, several foreign writers, both American and Continental, have declared in favour of an igneous origin for certain schists, so that the production of a parallel structure in igneous rocks may fairly be regarded as an established fact.The work which I have described in another paper (p. 517) led me to hope that we might be able to advance a step further. The intrusion of veins of granite in diorite, under pressure, suggested that at great depths, where pressures were at a maximum and chemical processes might be presumed to be most active, gneissic rocks of a more varied character might be produced. At the town of Galway I had seen gneisses which might have been produced in this way; but the crystalline schists of the Malvern Hills have furnished clear evidence of the genesis of some of the more complex gneisses, besides throwing additional light upon the production of the simpler schists. I am able to show that many of the schistose rocks of Malvern have an igneous origin, and I hope that the clues I},
issn = {0370-291X},
URL = {http://jgs.lyellcollection.org/content/43/1-4/525},
eprint = {http://jgs.lyellcollection.org/content/43/1-4/525.full.pdf},
journal = {Quarterly Journal of the Geological Society}
}